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-rw-r--r--net/wireless/util.c305
1 files changed, 305 insertions, 0 deletions
diff --git a/net/wireless/util.c b/net/wireless/util.c
index b94c8604ad7..d072bff463a 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -4,7 +4,9 @@
* Copyright 2007-2009 Johannes Berg <johannes@sipsolutions.net>
*/
#include <linux/bitops.h>
+#include <linux/etherdevice.h>
#include <net/cfg80211.h>
+#include <net/ip.h>
#include "core.h"
struct ieee80211_rate *
@@ -198,3 +200,306 @@ int cfg80211_validate_key_settings(struct key_params *params, int key_idx,
return 0;
}
+
+/* See IEEE 802.1H for LLC/SNAP encapsulation/decapsulation */
+/* Ethernet-II snap header (RFC1042 for most EtherTypes) */
+const unsigned char rfc1042_header[] __aligned(2) =
+ { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00 };
+EXPORT_SYMBOL(rfc1042_header);
+
+/* Bridge-Tunnel header (for EtherTypes ETH_P_AARP and ETH_P_IPX) */
+const unsigned char bridge_tunnel_header[] __aligned(2) =
+ { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0xf8 };
+EXPORT_SYMBOL(bridge_tunnel_header);
+
+unsigned int ieee80211_hdrlen(__le16 fc)
+{
+ unsigned int hdrlen = 24;
+
+ if (ieee80211_is_data(fc)) {
+ if (ieee80211_has_a4(fc))
+ hdrlen = 30;
+ if (ieee80211_is_data_qos(fc))
+ hdrlen += IEEE80211_QOS_CTL_LEN;
+ goto out;
+ }
+
+ if (ieee80211_is_ctl(fc)) {
+ /*
+ * ACK and CTS are 10 bytes, all others 16. To see how
+ * to get this condition consider
+ * subtype mask: 0b0000000011110000 (0x00F0)
+ * ACK subtype: 0b0000000011010000 (0x00D0)
+ * CTS subtype: 0b0000000011000000 (0x00C0)
+ * bits that matter: ^^^ (0x00E0)
+ * value of those: 0b0000000011000000 (0x00C0)
+ */
+ if ((fc & cpu_to_le16(0x00E0)) == cpu_to_le16(0x00C0))
+ hdrlen = 10;
+ else
+ hdrlen = 16;
+ }
+out:
+ return hdrlen;
+}
+EXPORT_SYMBOL(ieee80211_hdrlen);
+
+unsigned int ieee80211_get_hdrlen_from_skb(const struct sk_buff *skb)
+{
+ const struct ieee80211_hdr *hdr =
+ (const struct ieee80211_hdr *)skb->data;
+ unsigned int hdrlen;
+
+ if (unlikely(skb->len < 10))
+ return 0;
+ hdrlen = ieee80211_hdrlen(hdr->frame_control);
+ if (unlikely(hdrlen > skb->len))
+ return 0;
+ return hdrlen;
+}
+EXPORT_SYMBOL(ieee80211_get_hdrlen_from_skb);
+
+int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr)
+{
+ int ae = meshhdr->flags & MESH_FLAGS_AE;
+ /* 7.1.3.5a.2 */
+ switch (ae) {
+ case 0:
+ return 6;
+ case 1:
+ return 12;
+ case 2:
+ return 18;
+ case 3:
+ return 24;
+ default:
+ return 6;
+ }
+}
+
+int ieee80211_data_to_8023(struct sk_buff *skb, u8 *addr,
+ enum nl80211_iftype iftype)
+{
+ struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
+ u16 hdrlen, ethertype;
+ u8 *payload;
+ u8 dst[ETH_ALEN];
+ u8 src[ETH_ALEN] __aligned(2);
+
+ if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
+ return -1;
+
+ hdrlen = ieee80211_hdrlen(hdr->frame_control);
+
+ /* convert IEEE 802.11 header + possible LLC headers into Ethernet
+ * header
+ * IEEE 802.11 address fields:
+ * ToDS FromDS Addr1 Addr2 Addr3 Addr4
+ * 0 0 DA SA BSSID n/a
+ * 0 1 DA BSSID SA n/a
+ * 1 0 BSSID SA DA n/a
+ * 1 1 RA TA DA SA
+ */
+ memcpy(dst, ieee80211_get_DA(hdr), ETH_ALEN);
+ memcpy(src, ieee80211_get_SA(hdr), ETH_ALEN);
+
+ switch (hdr->frame_control &
+ cpu_to_le16(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) {
+ case cpu_to_le16(IEEE80211_FCTL_TODS):
+ if (unlikely(iftype != NL80211_IFTYPE_AP &&
+ iftype != NL80211_IFTYPE_AP_VLAN))
+ return -1;
+ break;
+ case cpu_to_le16(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS):
+ if (unlikely(iftype != NL80211_IFTYPE_WDS &&
+ iftype != NL80211_IFTYPE_MESH_POINT))
+ return -1;
+ if (iftype == NL80211_IFTYPE_MESH_POINT) {
+ struct ieee80211s_hdr *meshdr =
+ (struct ieee80211s_hdr *) (skb->data + hdrlen);
+ hdrlen += ieee80211_get_mesh_hdrlen(meshdr);
+ if (meshdr->flags & MESH_FLAGS_AE_A5_A6) {
+ memcpy(dst, meshdr->eaddr1, ETH_ALEN);
+ memcpy(src, meshdr->eaddr2, ETH_ALEN);
+ }
+ }
+ break;
+ case cpu_to_le16(IEEE80211_FCTL_FROMDS):
+ if (iftype != NL80211_IFTYPE_STATION ||
+ (is_multicast_ether_addr(dst) &&
+ !compare_ether_addr(src, addr)))
+ return -1;
+ break;
+ case cpu_to_le16(0):
+ if (iftype != NL80211_IFTYPE_ADHOC)
+ return -1;
+ break;
+ }
+
+ if (unlikely(skb->len - hdrlen < 8))
+ return -1;
+
+ payload = skb->data + hdrlen;
+ ethertype = (payload[6] << 8) | payload[7];
+
+ if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
+ ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
+ compare_ether_addr(payload, bridge_tunnel_header) == 0)) {
+ /* remove RFC1042 or Bridge-Tunnel encapsulation and
+ * replace EtherType */
+ skb_pull(skb, hdrlen + 6);
+ memcpy(skb_push(skb, ETH_ALEN), src, ETH_ALEN);
+ memcpy(skb_push(skb, ETH_ALEN), dst, ETH_ALEN);
+ } else {
+ struct ethhdr *ehdr;
+ __be16 len;
+
+ skb_pull(skb, hdrlen);
+ len = htons(skb->len);
+ ehdr = (struct ethhdr *) skb_push(skb, sizeof(struct ethhdr));
+ memcpy(ehdr->h_dest, dst, ETH_ALEN);
+ memcpy(ehdr->h_source, src, ETH_ALEN);
+ ehdr->h_proto = len;
+ }
+ return 0;
+}
+EXPORT_SYMBOL(ieee80211_data_to_8023);
+
+int ieee80211_data_from_8023(struct sk_buff *skb, u8 *addr,
+ enum nl80211_iftype iftype, u8 *bssid, bool qos)
+{
+ struct ieee80211_hdr hdr;
+ u16 hdrlen, ethertype;
+ __le16 fc;
+ const u8 *encaps_data;
+ int encaps_len, skip_header_bytes;
+ int nh_pos, h_pos;
+ int head_need;
+
+ if (unlikely(skb->len < ETH_HLEN))
+ return -EINVAL;
+
+ nh_pos = skb_network_header(skb) - skb->data;
+ h_pos = skb_transport_header(skb) - skb->data;
+
+ /* convert Ethernet header to proper 802.11 header (based on
+ * operation mode) */
+ ethertype = (skb->data[12] << 8) | skb->data[13];
+ fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA);
+
+ switch (iftype) {
+ case NL80211_IFTYPE_AP:
+ case NL80211_IFTYPE_AP_VLAN:
+ fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS);
+ /* DA BSSID SA */
+ memcpy(hdr.addr1, skb->data, ETH_ALEN);
+ memcpy(hdr.addr2, addr, ETH_ALEN);
+ memcpy(hdr.addr3, skb->data + ETH_ALEN, ETH_ALEN);
+ hdrlen = 24;
+ break;
+ case NL80211_IFTYPE_STATION:
+ fc |= cpu_to_le16(IEEE80211_FCTL_TODS);
+ /* BSSID SA DA */
+ memcpy(hdr.addr1, bssid, ETH_ALEN);
+ memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
+ memcpy(hdr.addr3, skb->data, ETH_ALEN);
+ hdrlen = 24;
+ break;
+ case NL80211_IFTYPE_ADHOC:
+ /* DA SA BSSID */
+ memcpy(hdr.addr1, skb->data, ETH_ALEN);
+ memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
+ memcpy(hdr.addr3, bssid, ETH_ALEN);
+ hdrlen = 24;
+ break;
+ default:
+ return -EOPNOTSUPP;
+ }
+
+ if (qos) {
+ fc |= cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
+ hdrlen += 2;
+ }
+
+ hdr.frame_control = fc;
+ hdr.duration_id = 0;
+ hdr.seq_ctrl = 0;
+
+ skip_header_bytes = ETH_HLEN;
+ if (ethertype == ETH_P_AARP || ethertype == ETH_P_IPX) {
+ encaps_data = bridge_tunnel_header;
+ encaps_len = sizeof(bridge_tunnel_header);
+ skip_header_bytes -= 2;
+ } else if (ethertype > 0x600) {
+ encaps_data = rfc1042_header;
+ encaps_len = sizeof(rfc1042_header);
+ skip_header_bytes -= 2;
+ } else {
+ encaps_data = NULL;
+ encaps_len = 0;
+ }
+
+ skb_pull(skb, skip_header_bytes);
+ nh_pos -= skip_header_bytes;
+ h_pos -= skip_header_bytes;
+
+ head_need = hdrlen + encaps_len - skb_headroom(skb);
+
+ if (head_need > 0 || skb_cloned(skb)) {
+ head_need = max(head_need, 0);
+ if (head_need)
+ skb_orphan(skb);
+
+ if (pskb_expand_head(skb, head_need, 0, GFP_ATOMIC)) {
+ printk(KERN_ERR "failed to reallocate Tx buffer\n");
+ return -ENOMEM;
+ }
+ skb->truesize += head_need;
+ }
+
+ if (encaps_data) {
+ memcpy(skb_push(skb, encaps_len), encaps_data, encaps_len);
+ nh_pos += encaps_len;
+ h_pos += encaps_len;
+ }
+
+ memcpy(skb_push(skb, hdrlen), &hdr, hdrlen);
+
+ nh_pos += hdrlen;
+ h_pos += hdrlen;
+
+ /* Update skb pointers to various headers since this modified frame
+ * is going to go through Linux networking code that may potentially
+ * need things like pointer to IP header. */
+ skb_set_mac_header(skb, 0);
+ skb_set_network_header(skb, nh_pos);
+ skb_set_transport_header(skb, h_pos);
+
+ return 0;
+}
+EXPORT_SYMBOL(ieee80211_data_from_8023);
+
+/* Given a data frame determine the 802.1p/1d tag to use. */
+unsigned int cfg80211_classify8021d(struct sk_buff *skb)
+{
+ unsigned int dscp;
+
+ /* skb->priority values from 256->263 are magic values to
+ * directly indicate a specific 802.1d priority. This is used
+ * to allow 802.1d priority to be passed directly in from VLAN
+ * tags, etc.
+ */
+ if (skb->priority >= 256 && skb->priority <= 263)
+ return skb->priority - 256;
+
+ switch (skb->protocol) {
+ case htons(ETH_P_IP):
+ dscp = ip_hdr(skb)->tos & 0xfc;
+ break;
+ default:
+ return 0;
+ }
+
+ return dscp >> 5;
+}
+EXPORT_SYMBOL(cfg80211_classify8021d);